All-frequency lighting generates rich visual effects that cannot be produced with current real-time relighting techniques, which are limited to very hard lights (point lighting) or very smooth lights (spherical harmonics).
Many realistic natural environments, such as detailed photographs of building interiors, contain features of all spatial frequencies, and scenes lit by such environments are enriched with subtle details in shadows and highlights. However, these effects are significantly blurred with soft harmonic lighting and become too harsh to be realistic with point lighting.
Currently the predominant technique in the art for interactive all-frequency relighting, non-linear approximation in a wavelet lighting basis (NLAWLB), is not practical because of the enormous precomputation costs and storage requirements. Therefore, what is needed is a method for all-frequency relighting that does not suffer the precomputation costs nor require the storage requirements of NLAWLB.